Photographic film camera with electric exposure meter built in



Aug. 15, 1939. 0. RISZDORFER PHOTOGRAPHIG FILM CAMERA WITH ELECTRIC EXPOSURE METER BUILT IN Filed Feb. 24, 1937 2 Sheets-Sheet 1 Aug. 15, 1939. .0. RISZDORFER PHOTOGRAPHIC FILM CAMERA WITH ELECTRIC EXPOSURE METER BUILT IN Filed Feb. 24, 1957 V 2 Sheets-Sheet 2' Patented Aug. 15, 1939 PHOTOGBAPHIO FILM CAMERA WI 'IH ELEC- TRIO EXPOSURE METER BUILT IN 66in Bissdorier, Budapest. Hungary Appliution February 24. 1937, Serial No. 127,495

In Hungary February 29, 1936 lClaim.

The invention relates to a photographic film camera with electric exposure meter built-in, in which camera the object lens is arranged on av displaceable object lens carrier capable of being displaced along the length of the tilted-up camera lid, and the light bellows of which is fixed between the spool carriers of the camera.

More particularly, the invention relates to a film folding camera. in which a photo-electric cell is mounted on the object lens carrier or inside the camera casing, the casing with the cell being sunk into a recess. between one of the spool boxes and the light bellows.

' Two embodiments oithe invention are illus- .trated in the drawings, of which Fig. 1 is a iront elevation of the opened camera, Fig. 2 a side elevation of the same camera in opened condition and Fig. 3 a sectionalong the line III- 111 of Fig. 1. Fig. 4 is a' irontelevation cram.

other embodiment of the camera. Fig. 5 is a side elevation view of the opened camera ac cording to Fig. 4. Fig. 6 illustrates diagrammat ically the electric connectionsjior both cameras. Fig. '7 illustrates a detail.

"I'he'camera casing tie in the usual manner constructed in such a manner'ns to enable'both film spools to be accommodated therein, notablyv one of the spools above and the other spool be low. For this purpm the rear wall 2 or the 'camera is capable of beingtilted down in the known manner and is pivotable around the hinge 3. Behind the closed lid 4 there are located inthe folded condition the bellows B and the obiect lens carrier 0 with the object lens superstructure. The object lens I is titted in the usual manner with a diaphragm. Around the object lens frame-2 the speed regulator ll of the shutter is arranged, the spring of the said regulator being capable of being tensioned by'positioning the ring II. The object lens carrier is held in the drawnout-position (Fig. 2) by the shear props l2. 5 a The camera according to the invention is fitted with a built-in exposure meter. Thismeter consists of the PhDtOvdleOtflC cell l2, which is ac commodatedinacasingmountcdon the object lens carrier 14. The photo-electric cell'is of square cross-section, a grid being arranged in the usual manner in front oi the layer sensitive to light,- as appears from Fig. 1. In the 5 l,whichisoiaslightlygreaterlcngththanhas been usual up to now,room isprovidsd below the spool box 2i to enable the photo-electric cell accommodated in the said room in the oonditionoitheeamera. Alongsidethis.

folded the-photo-elcctric cell I! a small box roomior ,o! the saidiinder. In the to zero, even though the adjusting 22 is built into the camera casing, which box contains a measuring instrument i5 oi a known type composed of a magnet and of an oscillating coil. The oscillating coil oi this instrument carries a pointer 48, the end of which is, when looking 5.

through the finder l1 arranged in a lateral position on the camera, visible in the field of vision finder a zero line it is-also provided, with which the pointer hasto bebrought into coincidence.

Alongside the measuring instrument Q two re sistances i9 and 20 capable of being regulated are provided in the box 22. The sliding contact 22 is capable of sliding on the resistance I2, whilst the sliding contact 24 is capable of sliding on the 1 resistance 20. Both resistances are in series with each other into the circuit of the photo-electric cell, as shown diagrammatically on Fig. 6. -The button of the sliding contact 22 cooperating with the resistance H9 is slidable go along a slot 25 provided in the plate 28 covering the box 22. The button of the sliding contact 2| slides along the slot 21 provided in the same plate.

The lever 8 is employed ior adjusting the distance for which the camera is focused. The button 28 is the release-button for the shutter. The lever 22 serves for the adjustment of the diaphragm opening. A resistance ll. is coordinated through a sliding contact to the diaphragm lever 30 29, whilst a resistance II is coordinated through another sliding contact to the adjusting ring ii of The resistance i2 serves for enabling the sensitivity of the film emulsion employed in the given case to be takeninto account. a I

The resistance 20 serves iorenablins the length of the time oi exposure to be determined in those cases when the pointer it will fail to adjust itself ring ii is ad- .iusted for one second.- In such case a time ex- 4 is vindicated and the value of the resistance 22 in the circuit of the photo-cell is adjusted, as required for to the zero mark 01 the contact 24 is a measure 0! thenecessary 5 the pointer is to adjust itself II at which time the position time. A scale having divisions corresponding to 'whole seconds should be provided alongside theslot 2-1, as shown by the series of dots 82, to translate the position of contact 24 into time units.

- "The Figs. 4 and 5 illustrate an embodiment, in

- which not only the photo-electric cell l2 but also the box 22 with the resistances and with the pointer instrument I! are mounted on the object lnl'igldand bsimilarpartlare u marked with the same reference numbers. This box carries here the reference number as. It contains, in the same way as in the preceding em-- bodiment, the two resistances capable of being regulated. The front covering plate 34 of the box is fitted with the two slots 35 and 36 for the sliding contacts of the two resistances. The box 33is, however, of shorter length than .in the preceding example, so that the part 3? of the plate 34 projects laterally beyond the box. This projecting part of the plate is fitted with a slot 38 in which a fixed index 3a is provided. Alongside this slot 38 a slot is provided in the box 33 also, through which slot the pointer (it of the electric measuring instrument projects. If the camera is opened, as shown on Fig. 5, it is possible by aiming through the finder l! to observe in the image field of the finder the slot 38 with the fixed index 39 as well as the pointer 4H.

It will be understwd that it is also possible to construct the camera described in such a manner thatnot only the box 22 should, as shown on Fig. 1, be arranged in a. fixed position in the camera casing, but that the photo-electric cell i3 should possibly also be arranged in a fixed position, alongside the box, in the camera casing.

The described arrangement of the photo-electric cell and of the regulating resistances in a film camera possesses the particular advantage of a compact arrangement, the height dimension of the camera being the only one of its dimensions that requires to be altered, ,whilst neither the width nor the thickness of the camera require to be altered. The slight increase of the height dimension of the camera does not constitute any drawback, as such increase amounts only to a small percentage of the height dimension usual and along a line spaced from the edge of saidopening opposite to the edge to which said plate is hinged, thereby providing a compartment within said opening and between the bellows and said second mentioned edge, an electric meter member mounted in one end of said compartment and a light sensitive cell connected to said -meter and mounted on said lens carrier for movement therewith, said cell being so positioned that it moves into the other end of said compartment when the lens carrier and its bellows are collapsed into said opening. v

. 0136i: RISZDORFER. 

